Need XML root element without end tag using JAXB STAX in combination

I am trying to marshal list to xml. As the xml contains list and I do not want to create separate class for outer tag I am using STAX and JAXB in combination.

The issue is I am getting element with end tag.
actual output

<WRAPPER>
	<ROOT att1="val1" att2="val2"></ROOT>
	<ROOT att1="val1" att2="val2"></ROOT>
</WRAPPER>

Expected Output

<WRAPPER>
    <ROOT att1="val1" att2="val2"/>
    <ROOT att1="val1" att2="val2"/>
</WRAPPER>

Class file

@XmlRootElement(name="ROOT")
@XmlAccessorType(XmlAccessType.FIELD)
public class ROOT {

	@XmlAttribute(name = "att1")
	String att1;
	
	@XmlAttribute(name = "att2")
	String att2;

	public String getAtt1() {
		return att1;
	}

	public void setAtt1(String att1) {
		this.att1 = att1;
	}

	public String getAtt2() {
		return att2;
	}

	public void setAtt2(String att2) {
		this.att2 = att2;
	}
}

Method

public static String marshal(List<ROOT> list)
	throws XMLStreamException, JAXBException, IOException {
	JAXBElement<ROOT> jaxb = null;
	String xmlString = null;
	if (!CollectionUtils.isEmpty(list)) {
		QName root = new QName("ROOT");
		XMLOutputFactory outputFactory = XMLOutputFactory.newFactory();
		StringWriter stringWriter = new StringWriter();
		
		XMLStreamWriter streamWriter = outputFactory.createXMLStreamWriter(stringWriter);
		streamWriter.writeStartElement("WRAPPER");
		JAXBContext jc = JAXBContext.newInstance(ROOT.class);
		Marshaller marshaller = jc.createMarshaller();
		for (ROOT t : list) {
			jaxb = new JAXBElement<ROOT>(root, ROOT.class, t);
			marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);
			marshaller.marshal(jaxb, streamWriter);
		}
		streamWriter.writeEndDocument();
		xmlString = stringWriter.toString();
		stringWriter.close();
		streamWriter.close();
		}
	return xmlString;
}

Problem is nillable cannot be applied to XmlRootElement

Although both expected and actual are technically equal I found no way to modify that in the way without creating additional wrapper class.